JP2020143294A - Elastomeric compositions and their applications - Google Patents

Abstract

To provide a reversion-free, condensation-curable, thermally conductive silicone adhesive composition that can be used to coat or encapsulate solid-state devices.SOLUTION: A condensation-curable, thermally conductive silicone adhesive composition comprises: a condensation-curable silyl terminated polymer having at least two hydroxyl functional groups per molecule; a silane cross-linker having at least 2 hydrolyzable groups, or at least 3 hydrolyzable groups, per molecule; at least one condensation catalyst selected from the group of titanates and/or zirconates; and thermally conductive fillers present in an amount of 70-93 wt.% of the composition.SELECTED DRAWING: None

Description

The present disclosure generally relates to thermally conductive silicone compositions, and elastomers and gels cured by condensation curing chemistry, and their uses.

Organosiloxane elastomers and resins due to their properties make them desirable for a variety of end applications in the electronics field. These materials are used to coat and encapsulate solid-state electronic devices, and the circuit boards on which these electronic devices are often mounted. To ensure long-term functioning of transistors, integrated circuits, and other solid-state electronic devices, protect them from contact with moisture, corrosive materials, and other impurities present in the environment in which they operate. There is a need. Organosiloxane compositions effectively protect solid devices from materials that can adversely affect their operation, but organosiloxane compositions typically occur during the operation of some solid devices. It does not have the thermal conductivity required to dissipate a large amount of heat.

Due to the rapid progress of electronics technology in recent years, it has become possible to reduce the size of solid-state devices in response to the demand for circuit miniaturization. Convective ventilation causes the amount generated at a rate that avoids damage to solid devices, as more of these devices are crowded in a given area and the overall size of the equipment containing these devices is reduced. It's no longer enough to dissipate the heat.

One way to increase heat dissipation is to increase the thermal conductivity of the material used to coat or enclose solid devices. This increase in thermal conductivity can be achieved by adding a thermally conductive filler to the coating or encapsulation material.

The resulting thermally conductive elastomer is an elastomeric material that is mainly used in electronics applications when good thermal conductivity and electrical insulation are required in the same material. For example, a thermally conductive elastomer can be used as an interface between a semiconductor electronic element and a metal heat sink.

Many electronic designs and applications are related by the ability to dissipate ohm heat generated during the operation of electronics. Many electronic elements, especially semiconductor elements, are easily destroyed at high temperatures. For this reason, the heat dissipation capacity is a limiting factor for the performance of the electronic element.

Since a metal heat sink having high thermal conductivity cannot be brought into direct contact with an electronic element due to its high conductivity, a heat conductive elastomer material is used as a heat conductive electricity between the electronic element and the metal heat sink. Used as an insulating interface. Thermal conductivity The thermal conductivity of elastomers is generally much lower than that of metal heat sinks. As a result, the thermal conductivity of the thermally conductive elastomer constrains the overall ability to dissipate ohm heat.

Commercially available silicone materials currently used to form encapsulants, implants and the like (eg gels) are based on addition curing chemistry, i.e., they are composed of silicon hydride groups and unsaturated carbon groups. It is typically cured by a reaction contributed by a catalyst, which is a platinum-based compound, and is expensive. Historically, in the industry, this type of additive curing composition was preferred for the above applications because it cures quickly through the compound body and becomes a curing material in minutes, but condensation curing. The system is much slower and in the titanate curing condensation process, for example, cures over up to 7 days per 6 mm depth of uncured material body. In the tin curing condensation system, it is cured in a shorter period of time, but it is not desired for electronics applications, for example, because it reverses (that is, depolymerizes) at a temperature higher than 80 ° C.

Materials made from hydrosilylated cured compositions are superior in terms of curing rate, but have some potential problems and / or disadvantages associated with their use. For example, they are generally cured at high temperatures (ie, above 100 ° C.) and may contain impurities, and expensive platinum-based curing catalysts include amine-containing compounds, sulfur-containing compounds, In addition, it is easily affected by phosphorus-containing compounds and may be poisoned, and may become non-curable due to catalyst deactivation.

It is known to those skilled in the art that an alkoxytitanium compound (ie, an alkyl titanate) is a suitable catalyst for the formulation of a one-component water-curable silicone (references: Noll, W .; Chemistry and Technology of Silicones, Academic Press). Inc., New York, 1968, p. 399, Michael A. Block, silicon in organic, organometricallic and polymer Chemistry, John Willey & sons, Inc. (2000), p. It is widely described that a titanate catalyst is used to formulate a surface or diffusion cured one-part condensation curable silicone elastomer. These formulations are typically available in one-part packages and are typically applied in layers thinner than 15 mm. It is known that deeper parts of the material result in uncured material, as layers thinner than 15 mm result in very slow diffusion of moisture into very deep parts. Surface or diffusion curing (eg, moisture curing / condensation curing) is initially performed by the formation of a cured film at the composition / air interface after the encapsulant / encapsulant is applied on the substrate surface. This is the case when the curing process of. After the surface film is formed, the curing rate is the rate of diffusion of moisture by air from the sealant / encapsulant interface into the interior (or nucleus) and from the interior (or nucleus) to the outside (or nucleus) of the material. It depends on the diffusion rate of the condensation reaction by-product / effluent to the surface) and the slow thickening of the cured film over time from the outside / surface to the inside / nucleus.

Titanium-based catalysts are not used in multi-component compositions designed to activate condensation curing in most of the product. These generally use other metal catalysts such as tin catalysts or zinc catalysts, such as dibutyltin dilaurate, tin octoate, and / or zinc octoate (Noll, W .; Chemistry and Technology of Silicones, Academic Press Inc. ., New York, 1968, p. 397). In silicone compositions stored prior to use in two or more parts, one part typically contains the water required to activate condensation hardening in most of the product, filling. Contains the agent. Unlike the above-mentioned diffusion curing one-part system, in the two-part condensation curing system, when mixed together, bulk curing is possible even in a portion deeper than 15 mm. In this case, the composition cures over most of the material (after mixing). When forming a film, it is only the first few minutes after application. Immediately afterwards, the product becomes solid throughout the mass. Since it is known that alkyl titanate catalysts completely hydrolyze to form silicone-insoluble tetrahydroxy titanates in the presence of large amounts of water, titanate catalysts cure these types of two-part compositions. Not used to force. In this titanium form, the catalytic efficiency is reduced, resulting in an uncured system.
There is a need for a two-part condensation-cured thermally conductive silicone that does not reverse reaction.

Noll, W. et al. Chemistry and Technology of Silicones, Academic Press Inc. , New York, 1968, p. 399 Michael A. Brook, silicon in organic, organometallic and polymer chemistry, John Wiley & sons, Inc. (2000), p. 285) Noll, W. et al. Chemistry and Technology of Silicones, Academic Press Inc. , New York, 1968, p. 397

The present invention is a multi-part condensation curable heat conductive silicone adhesive composition that does not react in reverse.
(I) At least one condensation-curable silyl-terminated polymer having at least one, typically at least two, hydroxyl functional groups per molecule.
(Ii)
A silane having at least 2 hydrolyzable groups or at least 3 hydrolyzable groups per molecule, and / or a silyl functional molecule having at least 2 silyl groups, each of which has at least 1 silyl group. A silyl functional molecule containing hydrolyzable groups, or a cross-linking agent selected from the group of mixtures thereof.
(Iii) With at least one condensation catalyst selected from the group of titanates and / or zirconates.
(Iv) One or more heat conductive fillers,
Including
Ingredients (i), (ii) and (iii) are not contained in the same part,
The molar ratio of total silicon-bonded hydroxyl groups to total hydrolyzable groups is 0.2: 1-2: 1 using silane cross-linking agents, or 0 using cross-linking agents for silyl functional molecules. .2: 1 to 10: 1 and a catalytic M-OR functional group for the total silicon-bonded hydroxyl group in the polymer (i) [where M is titanium or zirconium in the formula. ] Is included in the molar ratio of 0.01: 1 to 0.5: 1.
Provided is a condensation curable heat conductive silicone adhesive composition.

In addition, it is a thermally conductive silicone adhesive that is cured from the composition and does not react back.
(I) At least one condensation-curable silyl-terminated polymer having at least one, typically at least two, hydroxyl functional groups per molecule.
(Ii)
A silane having at least 2 hydrolyzable groups or at least 3 hydrolyzable groups per molecule, and / or a silyl functional molecule having at least 2 silyl groups, each of which has at least 1 silyl group. A silyl functional molecule containing hydrolyzable groups, or a cross-linking agent selected from the group of mixtures thereof.
(Iii) With at least one condensation catalyst selected from the group of titanates and / or zirconates.
(Iv) One or more heat conductive fillers,
Is a composition comprising
Ingredients (i), (ii) and (iii) are not contained in the same part,
The molar ratio of total silicon-bonded hydroxyl groups to total hydrolyzable groups is 0.2: 1-2: 1 using silane cross-linking agents, or 0 using cross-linking agents for silyl functional molecules. .2: 1 to 10: 1 and a catalytic M-OR functional group for the total silicon-bonded hydroxyl group in the polymer (i) [where M is titanium or zirconium in the formula. ] Is included in the molar ratio of 0.01: 1 to 0.5: 1.
A thermally conductive silicone adhesive, which is a composition, is also provided.

The adhesive is in the form of a gel or elastomer. It should be understood that for the purposes of this application, a "total hydrolyzable group" excludes both the water and silicon-bonded hydroxyl groups present in the composition.

The molar content of total silicon-bonded hydroxyl (Si-OH) is calculated for 100 g of the mixed formulation. The molar content of total silicon-bonded hydroxyl to the polymer is the hydroxyl functional group present in the polymer obtained by dividing the amount of the hydroxyl-containing polymer in g in 100 g of the mixed product by the number average molecular weight (Mn) of the polymer. Is equal to the product of the average number of (typically 2). If several hydroxyl functional polymers are present in the formulation, the sum of the molar contents of each polymer is added together to give the molar content of total silanol in the formulation.

The molar content of the total hydrolyzable group is calculated for 100 g of the mixed formulation. The molar content of hydrolyzable groups with respect to the substance is the amount of hydrolyzable group-containing molecules in 100 g of the mixed product in g units, or in the case of polymer molecules, divided by the number average molecular weight (Mn). It is equal to the product of the average number of hydrolyzable functional groups present in it. The sum of the molar contents of each molecule or polymer is added to give the molar content of the hydrolyzable group in the formulation.

Next, the molar ratio of total silicon-bonded hydroxyl groups to total hydrolyzable groups is calculated by dividing the molar content of silicon-bonded hydroxyl (Si-OH) groups by the total molar content of hydrolyzable groups. To. The M-OR value of the catalyst is obtained by dividing [(g of titanate catalyst) ^* (number of ORs in compound)] by (molecular weight of titanate catalyst).

The number average molecular weight (Mn) and weight average molecular weight (Mw) of silicone can also be determined by gel permeation chromatography (GPC). This technique is a standard technique and gives values of Mw (weight average), Mw (number average), and polydispersity index (PI) (where PI = Mw / Mn).

The Mn value shown in this application is determined by GPC and represents a typical value of the polymer used. If not obtained by GPC, Mn can also be obtained from calculations based on the absolute viscosity of the polymer.

The main advantages of these compositions and the resulting gels or elastomers are that they cure at room temperature and adhere to the substrate, are more resistant to impurities than platinum-cured silicones, and are higher than 80 ° C. Not causing a reverse reaction at temperature, in fact, they not only cure at room temperature, but also provide adhesion to the substrate at room temperature, while the addition curing system was heated above 80 ° C. The reason is that, in some applications, only adhesion is produced and some devices may be susceptible to high temperatures, or heating of large devices may be prohibited in terms of energy and cost. Therefore, it may become a problem.

Titanate / zirconate catalysts are useful for obtaining systems that do not reverse reaction when exposed to high temperatures and / or high humidity.

High thermal conductivity can be obtained, for example, with relatively low viscosity, ie 150,000 m-400,000 mPa. A silicone composition showing s is used and a large amount of filler is added, that is, at least 50% by weight, or 70 to 95% by weight, 70 to 93% by weight, or 80 to 90% by weight of the total composition. Considering this, after mixing the two parts together, it is about 2 W / mK or more.

The thermally conductive silicone adhesive composition for use in the reactor according to the present invention has good flow even when the thermal conductivity of the composition can be increased by blending a large amount of the thermally conductive filler. It can be embedded around a perishable substrate, has good physical properties after curing, has a slight change in physical properties over time due to heating or moist heat, and is a metal. And the adhesiveness to the organic resin is good. Also provided is a reactor embedded in the composition. As a result, the reliable performance of the reactor for applying the battery voltage between both ends of the motor after boosting is ensured.

The polymer (i) is at least one or / or water-curable / condensation-curable silyl-terminated polymer. Any suitable moisture / condensation curable silyl, including polydialkylsiloxane, alkylphenylsiloxane, or organic polymers with silyl-terminated groups, such as silylpolyether, silylacrylate and silyl-terminated polyisobutylene or any copolymer of the above. Terminal polymers can be used. The polymer (i) contains at least one hydroxyl group, and particularly preferably, the polymer can be selected from polysiloxane-based polymers containing two terminal hydroxyl groups.

Examples of suitable hydroxyl groups are -Si (OH) ₃ ,-( ^Ra ) Si (OH) ₂ ,-( ^Ra ) ₂ Si (OH), or-( ^Ra ) ₂ Si-R ^c-. SiR ^d _p (OH) _3-p [In the formula, each ^Ra is an independently monovalent hydrocarbyl group, for example an alkyl group, particularly an alkyl group having 1 to 8 carbon atoms (preferably a methyl group). ), Each of the R ^d groups is an alkyl group, preferably an alkyl group having 6 or less carbon atoms, and R ^c is a divalent hydrocarbon group having 12 or less carbon atoms. , One or more siloxane spacers having 6 or less silicon atoms may be interposed, and the value of p is 0, 1, or 2. ] Can be mentioned.

Preferably, the polymer (i) is of the general formula X ^3- A-X ¹ (1).
[In the formula, X ³ and X ¹ are selected independently of the siloxane group at the end of the hydroxyl group, and A is a siloxane polymer and / or an organic-containing polymer chain or a siloxane polymer chain. ].

Examples of a hydroxyl end group or a hydrolyzable group, X ³ or X ¹ , are −Si (OH) ₃ , − ( ^Ra ) Si (OH) ₂ , − ( ^Ra ) ₂ Si (OH) as defined above. ) Or-( ^Ra ) ₂ Si-R ^c- SiR ^d _p (OH) _3-p . Preferably, the X ³ and / or X ¹ terminal group is a hydroxydialkylsilyl group, such as a hydroxydimethylsilyl group.

An example of a suitable siloxane group in the polymer chain A of the formula (1) is one containing a polydiorganosiloxane chain. Therefore, the polymer chain A is preferably of the formula (2).
^{_{- (R 5 s SiO (4}} -s) / 2) - (2)
Wherein, R ⁵ are each independently an organic group, for example 1 to 10 hydrocarbyl group carbon atoms, optionally, one or more halogen groups are substituted, for example, chlorine or fluorine , S is 0, 1, or 2, typically about 2. ] Siloxane unit is included. Specific examples of the group R ⁵ include a methyl group, an ethyl group, a propyl group, a butyl group, a vinyl group, a cyclohexyl group, a phenyl group, a trill group, and a propyl group substituted with chlorine or fluorine, for example, 3,3,3-. Examples thereof include a trifluoropropyl group, a chlorophenyl group, a β- (perfluorobutyl) ethyl group, and a chlorocyclohexyl group. Preferably, at least some of the radicals R ^5, and preferably substantially all, methyl.

Typically, the viscosities of the above types of polymers are measured by the use of a Brookfield cone plate viscometer (RV DIII) using a cone plate and at 23 ° C., 1,000 to 300,000 mPa. s, or 1,000 to 100,000 mPa. It is an order of s.

Therefore, a typical polymer (i) containing a unit of formula (2) is a polydiorganosiloxane having a terminal silicon-bonded hydroxyl group, or terminal silicon, as defined above, which can be hydrolyzed using water. It is a polydiorganosiloxane having a bonded organic group. The polydiorganosiloxane may be a homopolymer or a copolymer. Mixtures of different polydiorganosiloxanes with terminal condensable groups are also suitable.

Alternatively, the polymer (i) may be an organic polymer having a silyl terminal group, each having at least one hydrolyzable group. Typical silyl-terminated polymer groups include silyl-terminated polyethers, silyl-terminated acrylates, and silyl-terminated polyisobutylene. The silyl group used is one or more of the above options as X ₁ and X ₃ above.

In the case of silyl polyether, the polymer chain is based on polyoxyalkylene units (organic). Such a polyoxyalkylene unit is preferably composed of a repeating oxyalkylene unit (-C _n H _2n- O-) and has an average formula (-C _n H _2n- O-) _m [in the formula, n is It is an integer of 2-4, and m is an integer of at least 4. ], Which mainly contains a linear oxyalkylene polymer. The number average molecular weight of each polyoxyalkylene polymer block may be in the range of about 300 g / mol to about 10,000 g / mol, but may be higher. Furthermore, the oxyalkylene units are not necessarily the same throughout the polyoxyalkylene monomer and may vary from unit to unit. The polyoxyalkylene block or polyoxyalkylene polymer is, for example, an oxyethylene unit (-C ₂ H _4- O-), an oxypropylene unit (C ₃ H ₆ O), or an oxybutylene unit (-C ₄ H _8- O-O). -), Or a mixture thereof.

Other polyoxyalkylene units include, for example, the structure,-[-R ^e- O- (-R ^f- O-) _w- Pn-CR ^g _2- Pn-O- (-R ^f- O-) _q. -R ^e ]-
Wherein, Pn is a 1,4-phenylene group, ^{R e} is, or different from each identical, the carbon atom a 2-8 divalent hydrocarbon radical, ^{R f} are each identical Or different, ethylene or propylene group, R ^g is the same or different, respectively, is a hydrogen atom or methyl group, and each of the subscripts w and q is in the range of 3-30. It is a positive integer. ] Units can be mentioned.

For the purposes of this application, "substitution" means that one or more hydrogen atoms in a hydrocarbon group have been replaced with another substituent. Examples of such substituents are halogen atoms such as chlorine atom, fluorine atom, bromine atom and iodine atom; containing halogen atom such as chloromethyl group, perfluorobutyl group, trifluoroethyl group and nonafluorohexyl group. Group; oxygen atom; oxygen atom-containing group such as (meth) acrylic and carboxyl group; nitrogen atom; nitrogen atom-containing group such as amino functional group, amide functional group, and cyano functional group; sulfur atom; and sulfur such as mercapto group. Examples include, but are not limited to, atomic-containing groups.

The cross-linking agent (ii) that can be used is generally water-curable,
A silane having at least 2 hydrolyzable groups or at least 3 hydrolyzable groups per molecule, and / or a silyl functional molecule having at least 2 silyl groups, each of which has at least 1 silyl group. It is a silyl functional molecule containing a hydrolyzable group.

In some examples, the cross-linking agent (ii) with two hydrolyzable groups may be considered as the chain extender, i.e. the polymer (i) having only one or two reactive groups. , When the polymer (i) has 3 or more reactive groups per molecule, it can be used for cross-linking. Therefore, in the cross-linking agent (ii), the number of silicon-bonded condensable groups (preferably hydroxyl groups and / or hydrolyzable groups) that are reactive with the condensable groups in the polymer (i) is two per molecule. It may be, or it may be 3 or 4.

For the purposes of the disclosure herein, the silyl functional molecule is a silyl functional molecule containing two or more silyl groups, each silyl group containing at least one hydrolyzable group. Thus, each disilyl functional molecule contains two silicon atoms, each with at least one hydrolyzable group, with the silicon atoms separated by organic or siloxane spacers. Typically, the silyl group on the disilyl functional molecule may be a terminal group. The spacer may be a polymer chain.

The hydrolyzable groups on the silyl group include an acyloxy group (eg, an acetoxy group, an octanoyloxy group, and a benzoyloxy group); a ketoximino group (eg, a dimethyl ketoximo group and an isobutylketoximino group). ); alkoxy groups (eg, methoxy, ethoxy, and propoxy groups); and alkenyloxy groups (eg, isopropenyloxy and 1-ethyl-2-methylvinyloxy groups). In some examples, the hydrolyzable group may include hydroxyl groups.

Examples of the silane cross-linking agent (ii) include alkoxyfunctional silane, oxymosilane, acetoxysilane, acetonoxime, and / or enoxysilane.

When the cross-linking agent is silane and the silane has only 3 silicon-bonded hydrolyzable groups per molecule, the fourth group is preferably a non-hydrolyzable silicon-bonded organic group. These silicon-bonded organic groups are preferably hydrocarbyl groups optionally substituted with halogens such as fluorine and chlorine. Examples of such a fourth group include alkyl groups (eg, methyl, ethyl, propyl, and butyl groups); cycloalkyl groups (eg, cyclopentyl and cyclohexyl groups); alkenyl groups (eg, vinyl). Groups and allyl groups); aryl groups (eg, phenyl and trill groups); aralkyl groups (eg, 2-phenylethyl groups), and by replacing all or part of the hydrogen in the organic groups described above with halogen. The obtained groups can be mentioned. The fourth silicon-bonded organic group may be methyl.

A typical silane is of formula (3).
R " _4-r RSi (OR ⁵ ) _r (3)
[In the formula, R ⁵ is described above and the value of r is 2, 3, or 4. ] Can be described. In typical silanes, R "represents methyl, ethyl, or vinyl or isobutyl. R" is selected from linear and branched alkyl, allyl, phenyl, and substituted phenyl, acetoxy, oxime. It is an organic group. In some examples, R ⁵ represents methyl or ethyl and r is 3.

Another type of suitable cross-linking agent (ii) has a molecular type of Si (OR ⁵ ) ₄ [in the formula, R ⁵ is as described above, or is propyl, ethyl, or methyl. ]belongs to. A partial condensate of Si (OR ⁵ ) ₄ can also be considered.

In one embodiment, the cross-linking agent (ii) has at least two silyl groups, each having at least 1 to up to 3 hydrolyzable groups, or each silyl group has at least 2 hydrolyzable groups. It is a silyl functional molecule having.

The cross-linking agent (ii) may be a disilyl functional polymer, i.e. a polymer containing two silyl groups, each containing at least one hydrolyzable group, of formula (4).
(R ⁴ O) _m (Y ¹ ) _3-m- Si (CH ₂ ) _x -((NHCH ₂ CH ₂ ) _t- Q (CH ₂ ) _x ) _n- Si (OR ⁴ ) _m (Y ¹ ) _{3 −M} (4)
[In the formula, R ⁴ is an alkyl group of C _{1 to 10} , and Y ¹ is an alkyl group containing 1 to 8 carbon atoms.
Q is a chemical group containing a heteroatom with a lone pair of electrons, for example amine, N-alkylamine, or urea, x is an integer of 1-6, respectively, and t is 0 or 1. m is 1, 2 or 3 independently, and n is 0 or 1. ] May be represented by.

The silyl (eg, disilyl) functional cross-linking agent (ii) may have a siloxane or organic polymer backbone. The suitable polymer cross-linking agent (ii) may have the same chemical structure of the polymer main chain as the polymer chain A represented by the above formula (1). In the case of such a siloxane-based or organic-based cross-linking agent, the molecular structure may be linear, branched, cyclic, or macromolecular, that is, a silicone or organic polymer chain having an alkoxy functional end group. Examples thereof include polydimethylsiloxane having at least one trialkoxy end, wherein the alkoxy group may be a methoxy group or an ethoxy group.

In the case of siloxane-based polymers, the viscosity of the cross-linking agent was 0.5 mPa. At 23 ° C. by using a Brookfield cone plate viscometer (RV DIII) using a cone plate (measured in the same manner as polymer (i)). s-80,000 mPa. It is in the range of s. Is suitable both of the aforementioned hydrolyzable groups, preferably hydrolyzable group is an alkoxy group, as such, terminal silyl ^{groups, -R a Si (OR b)} 2, -Si (OR ^b ) ₃ , -R ^a ₂ SiOR ^b , or-(R ^a ) ₂ Si-R ^c- SiR ^d _p (OR ^b ) _3-p [In the formula, ^Ra is independently and monovalent. A hydrocarbyl group, for example, an alkyl group, particularly an alkyl group having 1 to 8 carbon atoms (preferably a methyl group) is represented, and each of the R ^b group and the R ^d group independently has 6 or less carbon atoms. R ^c is a divalent hydrocarbon group, and one or more siloxane spacers having 6 or less silicon atoms may be interposed, and the value of p is 0, 1 or 2. is there. ] And the like. Typically, the terminal silyl group has two or three alkoxy groups, respectively.

From this, as the cross-linking agent (ii), alkyltrialkoxysilanes such as methyltrimethoxysilane (MTM) and methyltriethoxysilane, tetraethoxysilane, partially condensed tetraethoxysilane, vinyltrimethoxysilane and vinyltriethoxysilane. Examples thereof include alkenyltrialkoxysilanes such as silanes and isobutyltrimethoxysilanes (iBTMs). Other suitable silanes include ethyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, alkoxytrioximosilane, alkenyltrioximosilane, 3,3,3-trifluoropropyl. Trimethoxysilane, methyltriacetoxysilane, vinyltriacetoxysilane, ethyltriacetoxysilane, dibutoxydiacetoxysilane, phenyl-tripropionoxysilane, methyltris (methylethylketoximo) silane, vinyl -Tris-methylethylketoximo) silane, methyltris (methylethylketoximimino) silane, methyltris (isopropenoxy) silane, vinyltris (isopropenoxy) silane, ethylpolysilicate, n-propyl orthosilicate, ethylorthosilicate, dimethyltetraacetoxy Disiloxane, oxymosilane, acetoxysilane, acetonoxysilane, enoxysilane, and other such trifunctional alkoxysisilanes, as well as their partial hydrolysis condensation products; 1,6-bis (trimethoxysilyl) hexane, Bis (trialkoxysilylalkyl) amine, bis (dialkoxyalkylsilylalkyl) amine, bis (trialkoxysilylalkyl) N-alkylamine, bis (dialkoxyalkylsilylalkyl) N-alkylamine, bis (trialkoxysilylalkyl) ) Urea, bis (dialkoxyalkylsilylalkyl) urea, bis (3-trimethoxysilylpropyl) amine, bis (3-triethoxysilylpropyl) amine, bis (4-trimethoxysilylbutyl) amine, bis (4-) Triethoxysilylbutyl) amine, bis (3-trimethoxysilylpropyl) N-methylamine, bis (3-triethoxysilylpropyl) N-methylamine, bis (4-trimethoxysilylbutyl) N-methylamine, bis (4-Triethoxysilylbutyl) N-methylamine, bis (3-trimethoxysilylpropyl) urea, bis (3-triethoxysilylpropyl) urea, bis (4-trimethoxysilylbutyl) urea, bis (4-) Triethoxysilylbutyl) urea, bis (3-dimethoxymethi) Lucylpropyl) amine, bis (3-diethoxymethylsilylpropyl) amine, bis (4-dimethoxymethylsilylbutyl) amine, bis (4-diethoxymethylsilylbutyl) amine, bis (3-dimethoxymethylsilylpropyl) N-methylamine, bis (3-diethoxymethylsilylpropyl) N-methylamine, bis (4-dimethoxymethylsilylbutyl) N-methylamine, bis (4-diethoxymethylsilylbutyl) N-methylamine, bis (3-Dimethoxymethylsilylpropyl) urea, bis (3-diethoxymethylsilylpropyl) urea, bis (4-dimethoxymethylsilylbutyl) urea, bis (4-diethoxymethylsilylbutyl) urea, bis (3-dimethoxy) Ethylsilylpropyl) amine, bis (3-diethoxyethylsilylpropyl) amine, bis (4-dimethoxyethylsilylbutyl) amine, bis (4-diethoxyethylsilylbutyl) amine, bis (3-dimethoxyethylsilylpropyl) N-methylamine, bis (3-diethoxyethylsilylpropyl) N-methylamine, bis (4-dimethoxyethylsilylbutyl) N-methylamine, bis (4-diethoxyethylsilylbutyl) N-methylamine, bis (3-Dimethoxyethylsilylpropyl) urea, bis (3-diethoxyethylsilylpropyl) urea, bis (4-dimethoxyethylsilylbutyl) urea, and / or bis (4-diethoxyethylsilylbutyl) urea; bis ( Triethoxysilylpropyl) amine, bis (trimethoxysilylpropyl) amine, bis (trimethoxysilylpropyl) urea, bis (triethoxysilylpropyl) urea, bis (diethoxymethylsilylpropyl) N-methylamine; di or tri Alkoxysilane-terminated polydialkylsiloxane, di or trialkoxysilyl-terminated polyarylalkylsiloxane, di or trialkoxysilyl-terminated polypropylene oxide, polyurethane, polyacrylate; polyisobutylene; di or triacetoxy-terminated polydialkyl; polyarylalkylsiloxane; di or Examples thereof include trioxyiminosilyl-terminated polydialkyl; polyarylalkylsiloxane; di or triacetonoxy-terminated polydialkyl or polyarylalkyl. Further, the cross-linking agent (ii) used may contain any combination of the above two or more kinds.

The molar ratio of total silicon-bonded hydroxyl groups to total hydrolyzable groups is 0.5: 1-2: 1 using a silane crosslinker, or 0.5: 1 using a silyl functional crosslinker. It is 10: 1, or 0.5: 1 to 10: 1, or 0.75: 1-3: 1, or 0.75: 1 to 1.5: 1.

The composition further comprises a condensation catalyst. This increases the rate at which the composition cures. The catalyst selected for inclusion in a particular silicone composition will vary depending on the curing rate required.

Titanate-based and / or zirconate-based catalysts are of the general formula Ti [OR ²² ] ₄ or Zr [OR ²² ] ₄ [in the formula, R ²² may be the same or different, respectively, and is monovalent, 1 Represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms, which may be linear or branched, primary, secondary or tertiary. ] May be included. Optionally, the titanate and / or zirconate may contain a partially unsaturated group. Examples of R ²² include methyl group, ethyl group, propyl group, isopropyl group, butyl group, tertiary butyl group, and branched secondary alkyl group, for example, 2,4-dimethyl-3-pentyl group. However, it is not limited to these. Alternatively, if R ^22s are the same, then R ²² is an isopropyl group, a branched secondary alkyl group, or a tertiary alkyl group, especially a tertiary butyl. Examples of suitable titanates include tetra n-butyl titanate, tetra t-butyl titanate, titanium tetrabutoxide, and tetraisopropyl titanate. Examples of suitable zirconates include tetra n-propyl zirconate, tetra n-butyl zirconate and zirconium diethyl citrate.

Alternatively, titanate and / or zirconate may be chelated. Chelation can be carried out with any suitable chelating agent, such as alkylacetylacetonates, such as methyl or ethylacetonate. Alternatively, the titanate may be a monoalkoxy titanate that results in three chelating agents, such as 2-propanolato titanate, trisisooctadecanoato titanate, or diisopropyldiethylacetonate titanate.

The catalyst M-OR for the hydroxyl and / or hydrolyzable groups in the polymer (i) [where M is titanium or zirconium. ] The molar ratio of functional groups is contained in 0.01: 1 to 0.5: 1.

Two or more kinds of thermally conductive fillers (iv) differ in at least one property such as particle shape, average particle diameter, particle diameter distribution, and type of filler even if they are a single thermally conductive filler. It may be a combination of the heat conductive fillers of. Depending on the nature of the end use, the thermally conductive compositions described herein can contain as much as 70% to 95%, for example 70% to 93% of the thermally conductive fillers (above). Any suitable thermally conductive filler may be used. Examples include fillers of aluminum, aluminum oxide, zinc, and zinc oxide.

In some embodiments, metal fillers and inorganics, such as a combination of aluminum with an aluminum oxide oxide filler, an aluminum with a zinc oxide filler, or an aluminum with an aluminum oxide with a zinc oxide filler. Combinations with fillers may be used.

Alternatively, it may be desirable to use a combination of metal fillers, such as a first aluminum having a larger average particle size and a second aluminum having a smaller average particle size. By using a first filler having a larger average particle size and a second filler having a smaller average particle size than the first filler, the filling efficiency can be improved and the viscosity can be reduced. Can enhance heat transfer.

The shape of the thermally conductive filler particles is not particularly limited, but for circular or spherical particles, a large amount of the thermally conductive filler in the composition can prevent the viscosity from increasing to an undesired level. .. The average particle size of the thermally conductive filler is the type of thermally conductive filler selected, the exact amount to add to the curable composition, and the thickness of the junction of the device in which the cured product of the composition is used. It depends on various factors including the above.

In some specific cases, the thermally conductive filler has an average particle size in the range of 0.1 to 80 micrometers, or 0.1 to 50 micrometers, or 0.1 to 10 micrometers. May be good.

In a preferred embodiment, a mixture of thermally conductive fillers is prepared. Multiple fillers may or may not be the same chemical compound, for example.
a) Thermally conductive filler with an average particle size of 20-80 micrometers, or 30-50 micrometers, and / or b) Heat with an average particle size of 2-10 micrometers, or 2-6 micrometers Conductive fillers and / or c) Thermally conductive fillers with an average particle size of 0.1 to 1 micrometers, or 0.2 to 0.8 micrometers.
It is a mixture of two or more of the above, and is distinguished by the average particle size.

Any suitable thermally conductive filler can be used as a component (iv). Examples include metals such as bismuth, lead, tin, antimony, indium, cadmium, zinc, silver, copper, nickel, aluminum, iron, and metallic silicon. The alloy of bismuth, lead, tin, antimony, indium, cadmium, zinc, silver and aluminum is an alloy composed of two or more metals selected from the group consisting of iron and metallic silicon. Examples of the metal oxide include alumina, zinc oxide, silicon oxide, magnesium oxide, beryllium oxide, and chromium oxide and titanium oxide. Metal hydroxides include magnesium hydroxide, aluminum hydroxide, barium hydroxide, and calcium hydroxide. As the metal nitride, boron nitride includes aluminum nitride and silicon nitride. Metal carbides and silicon carbide include boron carbide and titanium carbide. Examples of the metal silicide include magnesium silicide, titanium silicide, VDD, zirconium, tantalum silicide, niobium silicide, chromium silicide, tungsten silicide, and molybdenum silicide. As carbon, diamond, graphite, fullerene, carbon nanotube, graphene includes activated carbon and atypical carbon black. Soft magnetic alloys, Fe-Si alloys, Fe-Al alloys, Fe-Si-Al alloys, Fe-Si-Cr alloys, Fe-Ni alloys, Fe-Ni-Co alloys, Fe-Ni-Mo alloys, Fe-Co Alloys, Fe-Si-Al-Cr alloys, Fe-Si-B alloys, and Fe-Si-Co-B alloys. Examples of the ferrite include Mn-Zn ferrite, Mn-Mg-Zn ferrite, Mg-Cu-Zn ferrite, Ni-Zn ferrite, and Ni-Cu-Zn ferrite and Cu-Zn ferrite.

Preferably, the thermally conductive filler (iv) is selected from silver powder, aluminum powder, aluminum oxide powder, zinc oxide powder, aluminum powder or graphite nitride, at least one powder (powder) and /. Or it is a fiber. As a further alternative, further, in the compositions of the present invention, metal oxide powders or metal nitride powders are particularly preferred when electrical insulation is required. In one embodiment, the filler (iv) is a mixture of aluminum oxide, optionally pretreated, of various diameters, allowing optimum filling and low viscosity.

The thermally conductive filler may be a melt-soluble filler and may contain Bi, Ga, In, Sn, or an alloy thereof. The meltable filler may optionally further contain Ag, Au, Cd, Cu, Pb, Sb, Zn or a combination thereof. Examples of suitable meltable fillers include Ga, In-Bi-Sn alloys, Sn-In-Zn alloys, Sn-In-Ag alloys, Sn-Ag-Bi alloys, Sn-Bi-Cu-Ag alloys, etc. Examples thereof include Sn-Ag-Cu-Sb alloys, Sn-Ag-Cu alloys, Sn-Ag alloys, Sn-Ag-Cu-Zn alloys, and combinations thereof. The meltable filler can have a melting point in the range of 50-250 ° C, or 150-225 ° C. The meltable filler may be a eutectic alloy, a non-eutectic alloy, or a pure metal. Meltable fillers are commercially available.

The thermally conductive filler and / or, if present, the anhydrous reinforcing filler and / or the bulk filler may be surface-treated with a treatment agent, optionally. Treatment agents and treatment methods are known in the art and surface treatment of fillers is typically with, for example, fatty acids or fatty acid esters, such as stearate, or organosilanes, organosiloxanes, or organosilazanes. For example, it is carried out with hexaalkyldisilazane or short chain siloxane diol. In general, the surface treatment makes the filler hydrophobic, which facilitates the handling and availability of homogeneous mixtures with other components in the composition. Silane, for example
R ⁵ _e Si (OR ⁶ ) _4-e
Wherein, R ⁵ is a substituted or unsubstituted, 6-20 monovalent hydrocarbon group of carbon atoms, e.g., hexyl group, octyl group, dodecyl group, an alkyl group, such as tetradecyl and octadecyl, Further, it is an aralkyl group such as a benzyl group and a phenylethyl group, preferably an alkyl group having 6 to 20 carbon atoms, R ⁶ is an alkyl group having 1 to 6 carbon atoms, and the letter e is 1, 2 or 3. ] May also be used as a treatment agent for the filler.

The cured gel or elastomer is typically made from a condensation curable gel or elastomer composition stored in two parts. The two-part composition may be mixed using any suitable standard two-part mixer with a dynamic or static mixer, optionally from the device for use in the intended application. Be dispensed.

In one embodiment, the condensation curable gel composition is stored in two parts, the parts of which are:
a) Polymer (i) and cross-linking agent (ii) in one part, and polymer (i) and catalyst (iii) in the other part.
b) When a cross-linking agent (ii) is used in one part and a polymer (i) and a catalyst (iii) are used in the other part, or c) two or more kinds of polymers (i) are used in one part, the first polymer is used in one part. (I) and the cross-linking agent (ii), and the second polymer (i) and catalyst (iii) in the other part,
d) Polymer (i) in one part, and cross-linking agent (ii) and catalyst (iii) in the other part.
It may be divided as.
In each case, if there is an optional filler, especially a water-containing filler, the filler and catalyst are not in the same part. Typically, the filler is mixed with the polymer (i) in the base portion, which may also contain other additives, if present.

The thermally conductive filler may be present in either one or both of the two-part compositions.

In addition to the above components, an optional component may be blended in the silicone gel composition as long as the object of the present invention is achieved. Examples of optional components include anhydrous reinforcing fillers and / or anhydrous increasing fillers, heat resistance imparting agents, cold resistance imparting agents, flame retardants, thixotropy imparting agents, pigments, adhesion promoters, surfactants, and melts. Agents, acid receptors, corrosion resistant additives, dyes, and any suitable combination thereof can be mentioned.

If desired, the composition may incorporate other types of fillers that do not have to be anhydrous, such as conductive fillers, such as metal and inorganic fillers, or combinations thereof. .. Examples of the metal filler include metal particles and metal particles having a layer on the surface of the particles. The layer on the surface of these particles may be, for example, a metal nitride layer or a metal oxide layer. Examples of suitable metal fillers include metal particles selected from the group consisting of aluminum, copper, gold, nickel, tin, silver, and combinations thereof, or aluminum particles. A further example of a suitable metal filler is the metal particles having a layer on its surface selected from the group consisting of aluminum nitride, aluminum oxide, copper oxide, nickel oxide, silver oxide, and combinations thereof. Can be mentioned. For example, the metal filler may contain aluminum particles having an aluminum oxide layer on its surface.

Anhydrous inorganic fillers include, for example, Onix; metal oxides such as aluminum trihydrate, carbon black, hollow glass beads, aluminum oxide, beryllium oxide, magnesium oxide, and zinc oxide; such as aluminum nitride and boron nitride. Nitride: Carbides such as silicon carbide and tungsten carbide, and combinations thereof can be mentioned. Further fillers include barium titanate, carbon fiber, diamond, graphite, magnesium hydroxide, and combinations thereof.

Examples of anhydrous reinforcing fillers and / or anhydrous bulk fillers are precipitated silica and ground silica, precipitated calcium and ground calcium carbonate, treated silica, glass beads, carbon black, graphite, carbon nanotubes, quartz, and talc. , Shredded fibers such as shredded KEVLAR®, or combinations thereof. The filler is R ₃ SiO _1/2 unit and SiO _4/2 unit [In the formula, R is a hydroxyl group or a hydrocarbon group bonded directly to a silicon atom or via an oxygen atom. ] May be included in the siloxane resin. Further, these optional fillers may be treated with a filler treatment agent as described above.

Suitable adhesion promoters are of the formula R ¹⁴ _h Si (OR ¹⁵ ) _(4-h) , [in the formula, the subscript h is 1, 2, or 3, or h is 3. ] Alkoxysilane. R ¹⁴ is an independently monovalent organic functional group. R ¹⁴ is an epoxy functional group such as glycidoxypropyl or (epoxycyclohexyl) ethyl, an amino functional group such as aminoethylaminopropyl or aminopropyl, a mercapto functional group such as methacryloxypropyl or mercaptopropyl, or an unsaturated organic group. It may be. Each R ¹⁵ is independently an unsaturated saturated hydrocarbon group having at least one carbon atom. R ¹⁵ may have 1 to 4 carbon atoms, or 1 to 2 carbon atoms. Examples of R ¹⁵ include methyl, ethyl, n- propyl, and isopropyl.

When using an adhesion enhancer, the composition exhibits good adhesion to various substrates, especially if the filler has been pretreated. In compositions containing non-pretreatment fillers, the use of pre-applied primers typically provides good adhesion.

Further examples of suitable adhesion enhancers include glycidoxypropyltrimethoxysilane and combinations of glycidoxypropyltrimethoxysilane with an aluminum chelate or a zirconium chelate.

The curable composition, if present, may contain 0.01-2% by weight, or 0.05-2% by weight, or 0.1-1% by weight of the adhesion accelerator, depending on the weight of the composition. Good. Preferably, the rate of hydrolysis of the adhesion promoter should be slower than the rate of hydrolysis of the crosslinker so that it favors the diffusion of the molecule towards the substrate rather than incorporating it into the product network.

Suitable surfactants include silicone polyethers, ethylene oxide polymers, propylene oxide polymers, copolymers of ethylene oxide and propylene oxide, other nonionic surfactants, and combinations thereof. The composition may contain up to 0.05% surfactant based on the weight of the composition.

The composition may contain up to 2% flux based on the weight of the composition. Molecules containing chemically active functional groups such as carboxylic acids and amines can be used as fluxes. Such fluxes include aliphatic acids such as succinic acid, avietic acid, oleic acid, and adipic acid; aromatic acids such as benzoic acid; aliphatic amines and derivatives thereof, such as triethanolamine, hydrochloric acid of amines. Hydrobromate salts of salts and amines can be mentioned. Flux is known in the art and is commercially available.

Suitable acid receptors include magnesium oxide, calcium oxide, and combinations thereof. The composition may, where appropriate, contain up to 2% acid receptors based on the weight of the composition.

Examples of the corrosion resistant additive include a nitrogen / sulfur-containing heterocyclic compound having a triazole structure, a thiadiazole structure, a benzotriazole structure, a mercaptothiazole structure, a mercaptobenzothiazole structure, or a benzoimitazole structure.

Also provided herein is a method for producing an elastomer or gel as described above, which allows the above two parts of the composition to be intermixed and cured. After mutual mixing in one embodiment, the condensation curable gel composition is used with suitable dispensers such as, for example, curtain coaters, sprayers, die coaters, dip coaters, extrusion coaters, knife coaters, and screen coaters. Can be applied on a substrate and provides a coating on this substrate during gel formation.

According to the above, gels or elastomers can be used in a wide range of applications, for example as encapsulants / implants in electronic articles.

The article may be an electronic article for electric power, for example, an electronic element with a gel on top.

The article may be an electronic article for electric power, eg, an electronic element on which a material composition is provided, whereby the cured material either partially or completely encapsulates the electronic element. Alternatively, the electronic article may be an integrated circuit (IC) or light emitting diode (LED) system, or may be a printed circuit board (PCB).

Silicone materials such as those described above are designed for use in optical and electronic applications, including microelectronic and macroelectronic applications as well as optelectronic and thermally conductive electronics applications, such as the manufacture of thermally conductive adhesives. Further, since the silicone material of the present invention can be made transparent, it can be suitable for use in a light emitting semiconductor element such as an LED.

Cured silicone adhesives prepared from such curable silicone compositions can include electrical or electronic elements, or various substrates such as electrical or electronic components, especially gold, silver, aluminum, copper, and polybutylene tere. Metal substrates such as FR4, nylon, polycarbonate, Lucite (which is polymethylmethacrylate, PMMA), polybutylene terephthalate (PBT), and liquid crystal polymers such as Solvay Chemicals (Hoston, Tex.77098 USA. ) Can be adhered to a polymer substrate such as Xydar®.

The electrical or electronic component and / or the electrical or electronic component can be filled with a silicone material and by any suitable method, for example, the electrical or electronic component to be protected is brought into contact with the silicone material. After that, the composition can be filled by curing by condensation curing, that is, by leaving it at room temperature.

Any suitable electrical or electronic component can be sealed with the silicone material as described above, but the silicone material of the present invention can suppress the generation of bubbles and cracks and is under high temperature conditions. Also, since the bonding to electrical or electronic components is well shown, it can be used in power devices used under high temperature conditions, especially power devices such as motor control, transport motor control, power generation systems, or space transport systems. It can be used advantageously.

Further, as a reason, the silicone material of the present invention has a certain degree of cold resistance in addition to the heat resistance required for the Si—C semiconductor chip (for example, heat resistance of 180 ° C. or higher). The electronic article may be a power module, eg, one or more of the aforementioned devices for the aforementioned power converters, inverters, boosters, traction control, industrial motor control, power distribution and power transport systems, in particular. It may be in a power device that requires the ability to withstand a significant temperature difference, and the durability and reliability of such a power device can be improved.

Examples of such electric power devices that require heat resistance and cold resistance include motor control used in cold regions, such as general-purpose inverter control, servo motor control, machine tools, or elevators, electric vehicles, and hybrid vehicles. Alternatively, a motor control for rail transportation used in a cold region, a power generation system used in a cold region, for example, a solar generator, a wind power generator, a fuel cell generator, a space transportation system used in space, and the like can be mentioned. The "cold region" refers to an region where the temperature is lower than 0 ° C.

Further, the silicone material can also be used for sealing an electric component or an electronic component having a structure in which the space between electrodes in the electric component or the electronic component, the space between the electric elements, or the space between the electric element and the package is narrow. Alternatively, it is also effective for sealing electrical or electronic components having a structure that cannot follow the expansion and contraction of the silicone material. For example, it can be an electrical circuit or module on which electrical elements such as semiconductor devices, capacitors, resistors, etc. are mounted, ie, various sensors, such as pressure sensors generally sealed or filled with silicone material, and automotive ignition. It can be used for vessels, regulators, etc.

Electronic elements include chips such as silicon chips or silicon carbide chips, one or more wirings, one or more sensors, one or more electrodes, integrated circuits (ICs) such as hybrid ICs, power devices, Schottky gate bipolar transistors ( IGBTs), rectifiers such as Schottky diodes, PIN diodes, PIN / Schottky combination (MPS) rectifiers, and junction barrier diodes, bipolar junction transistors (BJTs), thyristors, metal oxide electric field effect transistors (MOSFETs), high electron transfer. It can be defined as a degree transistor (HEMT), an electrostatic induction transistor (SIT), a power transistor, and the like.

The electronic article may include an electronic element and a first layer. The first layer is not particularly limited, and is limited to semiconductor, dielectric, metal, plastic, carbon fiber mesh, metal foil, perforated metal foil (mesh), filled or unfilled plastic film (polyamide sheet, polyimide sheet, polyethylene naphthalate). It may be a sheet, a polyethylene terephthalate polyester sheet, a polysulfone sheet, a polyetherimide sheet, a polyphenylene sulfide sheet, etc.), or a woven fabric or a non-woven fabric base material (glass fiber cloth, glass fiber mesh, aramid paper, etc.). Alternatively, the first layer may be further specified as a semiconductor and / or dielectric film.

The silicone material may be sandwiched between the electronic element and the first layer and / or provided in direct contact with it on the first layer and / or in direct contact with it on the electronic element. It may have been. If the silicone material is provided on the first layer in direct contact with it, the silicone material may be further provided on the electronic element, but one or more between the silicone material and the electronic element. It may include layers or structures.

The disclosure also provides the aforementioned method of forming an electronic article. The method may include one or more of the aforementioned steps of forming a gel, providing a gel, and / or providing an electronic element.

Typically, the method is to apply the curable composition described above onto an electronic element, and to cure the composition so that the electron is formed under conditions sufficient to form a gel without damaging the element. Includes forming a gel on the element. The gel may be formed on an electronic element. Alternatively, the gel may be formed away from the electronic element and then placed on the electronic element.

In addition, a method for producing a gel as described above is also provided in the present specification, whereby the composition of the above two parts is mutually mixed and cured.

After mutual mixing in one embodiment, the condensation curable gel composition is dispensed with suitable dispensers such as, for example, curtain coaters, sprayers, die coaters, bead applications, dip coaters, extrusion coaters, knife coaters, and screen coaters. Can be applied on a substrate using the to obtain a coating on this substrate during gel formation.

The above-mentioned silicone gel has excellent heat resistance at a high temperature of 180 ° C. or higher, and the gel is less likely to deteriorate when used at this high temperature for a long period of time.

In addition, the gel can also be used to seal electrical or electronic components in structures where the space between electrodes within the electrical or electronic component, the space between the electrical elements, or the space between the electrical element and the package is narrow. It is also effective for sealing electric or electronic components having a structure that cannot follow the expansion and contraction of the silicone gel. For example, an electric circuit or module in which an electric element such as a semiconductor element, a capacitor, or a resistor is mounted, that is, a pressure sensor generally sealed or filled with various sensors, for example, a silicone gel, an automobile igniter. , Can be used for regulators, etc.

The disclosure also provides the aforementioned method of forming an electronic article. The method may include one or more of the aforementioned steps of forming a gel, providing a gel, and / or providing an electronic element. Typically, the method comprises comprising the curable composition described above on an electronic element, and the electron under conditions sufficient to cure the composition and form a gel without damaging the element. Includes forming a gel on the element. The gel may be formed on an electronic element. Alternatively, the gel may be formed away from the electronic element and then placed on the electronic element.

Material Thermally Conductive Filler Filler 1 is aluminum oxide having an average particle size of about 40 μm (D50 determined by laser diffraction).
The filler 2 is aluminum oxide having an average particle size of about 3.1 μm (D50 determined by laser diffraction), and the filler 3 is an average particle size of about 0.44 μm (D50 determined by laser diffraction). It is aluminum oxide showing.

Adhesion accelerator 1
With 53.5% by weight of methyltrimethoxysilane,
With 27.4% by weight 3-glycidoxypropyltrimethoxysilane,
It is a mixture with 21.8% by weight of pre-condensed 3-aminopropyltriethoxysilane.

Examples 1-3 and Comparative Examples Base and hardener formulations were prepared according to the compositions shown in Table 1. Different compositions were prepared as follows. Unless otherwise indicated, all viscosity measurements were obtained at 23 ° C. using a Brookfield cone plate viscometer (RV DIII) and a cone plate optimal for viscosity. The results obtained from the cured gel of the composition are shown in Table 2.

18.15 g of OH-dimethyl-terminated polydimethylsiloxane (viscosity 2,000 mmPa.s) and 19.95 g of OH-dimethyl-terminated polydimethylsiloxane (viscosity 13,500 mPa.s) for the bases of Examples 1 and 2 and Comparative Example 1. Was mixed in a high-speed mixer at 2300 rpm for 30 seconds. Then, 198.22 g of the filler 1 was added and mixed in a high-speed mixer at 2300 rpm for 30 seconds. Then, 60.03 g of filler 2 was added and mixed in a high speed mixer at 2300 rpm for 30 seconds. Finally, 33.64 g of filler 3 was added and mixed in a high speed mixer at 2300 rpm for 30 seconds.

Base for Example 3 6.60 g of OH dimethyl-terminated polydimethylsiloxane (viscosity 2,000 mPa.s) with 7.26 g of OH-dimethyl-terminated polydimethylsiloxane (viscosity 13,500 mPa.s) in a high speed mixer. Mixing was performed at 2300 rpm for 30 seconds. Next, 72.05 g of untreated filler 1 was added and mixed in a high speed mixer at 2300 rpm for 30 seconds. Then, 21.82 g of untreated filler 2 was added and mixed in a high speed mixer at 2300 rpm for 30 seconds. Then 12.23 g of untreated filler 3 was added and mixed in a high speed mixer at 2300 rpm for 30 seconds. Finally, 0.05 g of tetra n-butyl titanate was added and mixed 3 times in a high speed mixer at 2300 rpm for 30 seconds.

9.91 g of the curing agent for Example 1 of trimethoxysilyl-terminated polydimethylsiloxane (viscosity 56,000 mPa.s) was added into the vessel and mixed with 0.495 g of the adhesion accelerator 1. Then, 26.94 g of filler 1 was added and mixed in a high speed mixer at 2300 rpm for 30 seconds. Then 8.04 g of filler 2 was added and mixed in a high speed mixer at 2300 rpm for 30 seconds. Then, 4.55 g of the filler 3 was added and mixed in a high speed mixer at 2300 rpm for 30 seconds. Finally, 0.074 g of tetra n-butyl titanate was added and mixed 3 times in a high speed mixer at 2300 rpm for 30 seconds.

A curing agent for Example 2 19.96 g of trimethoxysilyl-terminated polydimethylsiloxane (viscosity 56,000 mPa.s) was added into the vessel and mixed with 0.252 g of the adhesion accelerator 1. Then 27.07 g of filler 1 was added and mixed in a high speed mixer at 2300 rpm for 30 seconds. Then 8.08 g of filler 2 was added and mixed in a high speed mixer at 2300 rpm for 30 seconds. Then, 4.57 g of the filler 3 was added, and the mixture was mixed three times at 2300 rpm for 30 seconds in a high-speed mixer. Finally, 0.075 g of tetra n-butyl titanate was added and mixed in a high speed mixer at 2300 rpm for 30 seconds.

9.91 g of the curing agent for Example 3 of trimethoxysilyl-terminated polydimethylsiloxane (viscosity 56,000 mPa.s) was added into the vessel and mixed with 0.495 g of the adhesion accelerator 1. Then 26.94 g of untreated filler 1 was added and mixed in a high speed mixer at 2300 rpm for 30 seconds. Then 8.04 g of untreated filler 2 was added and mixed in a high speed mixer at 2300 rpm for 30 seconds. Then 4.55 g of untreated filler 3 was added and mixed in a high speed mixer at 2300 rpm for 30 seconds. Finally, 0.074 g of tetra n-butyl titanate was added and mixed 3 times in a high speed mixer at 2300 rpm for 30 seconds.

About 95 g of base was filled in one cylinder of the two-part cartridge and about 40 g of hardener was filled in the other cylinder of the two-part cartridge. The cartridge has a volume ratio of 2: 1 to the base hardener. A stationary mixer was used to mix both raw materials from the cartridge and dispense the materials to form a plate.

Plates were then tested for lap shear strength and lap shear elongation on aluminum anodic oxide according to this method. The two anodized aluminum substrates have dimensions of 100 x 25 x 2 mm ³ and are glued with a thermally conductive adhesive, resulting in a bonded volume of 25 x 25 x 1 mm for a predetermined period (7 days or (28 days), left at 23 ° C. and 50% relative humidity to cure. The lap shear test piece was mounted in a tension gauge (Zwick) using an L-shaped pinch for holding and the test was carried out. A preload of 0.05 MPa was applied at a rate of 5.5 mm / min. The lap shear test was performed at 50 mm / min until a force drop of 50% of the maximum force was measured. At this point, elongation is measured (and recorded in%). The maximum measured force is reported as the shear strength (in MPa).

Thermal conductivity was measured on a TIMA tester with ASTM D5470-12. The test was performed on a sample cured for 7 days (thickness 1, 2, and 3 mm, all having the same diameter of 7.83 mm) under a pressure of 2N. Under this force condition, the adhesion between the material and the measuring probe can be ensured in combination with the flexibility of the product.

The gelation time was determined as the time during which a 30 mL aluminum cup filled with material could be turned upside down without significant movement of the product.

The state of adhesive failure is that the sealing agent is attached to the base material at the boundary surface of the sealing agent beads applied on the base material using a cutter, and the material is manually peeled off (finger peeling test). ) And judged. CF means cohesive failure, that is, the failure occurs inside the elastomer. AF means adhesive fracture, that is, the fracture occurs at the substrate / elastomer interface. After placing the sample at + 150 ° C for 30 minutes, the temperature was changed from one extreme to the other in <3 minutes by moving the chamber for <10 seconds, and the temperature was changed to -40 ° C for 30 minutes to apply thermal shock. Carried out.

The agglomeration percentages of Examples 1, 2, and 3 after fracture on aluminum anodic oxide were higher than in Comparative Example 1, and the adhesive profile provided by the titanate catalyst-based composition according to the present invention was cured. It was emphasized that the composition was superior to the tin-catalyzed composition of Comparative Example 1 even if it was slowed down.

Also, elongation at the break point is higher in titanate-based formulations, which is an important parameter for thermally conductive adhesives. Formulations with higher elongation and lower modulus are more efficient materials to adapt to the thermal stresses in the application.

A typical silane is of formula (3).
^{_{R "4-r S i (}} OR 5) r (3)
[In the formula, R ⁵ is described above and the value of r is 2, 3, or 4. ] Can be described. In typical silanes, R "represents methyl, ethyl, or vinyl or isobutyl. R" is selected from linear and branched alkyl, allyl, phenyl, and substituted phenyl, acetoxy, oxime. It is an organic group. In some examples, R ⁵ represents methyl or ethyl and r is 3.

Claims (20)

(I) At least one condensation-curable silyl-terminated polymer having at least one, typically at least two, hydroxyl functional groups per molecule.
(Ii)
A silane having at least 2 hydrolyzable groups or at least 3 hydrolyzable groups per molecule, and / or a silyl functional molecule having at least 2 silyl groups, each of which has at least 1 silyl group. A silyl functional molecule containing hydrolyzable groups, or a cross-linking agent selected from the group of mixtures thereof.
(Iii) With at least one condensation catalyst selected from the group of titanates and / or zirconates.
(Iv) One or more heat conductive fillers,
Including
The components (i), (ii) and (iii) are not contained in the same part, and the molar ratio of total silicon-bonded hydroxyl groups to total hydrolyzable groups is 0.2: 1 using a silane crosslinker. ~ 2: 1 or 0.2: 1 to 10: 1 using a cross-linking agent for the silyl functional molecule, and a catalytic M-OR functional group for the total silicon-bonded hydroxyl group [in the formula]. , M is titanium or zirconium. ] Is included in the molar ratio of 0.01: 1 to 0.5: 1.
A multi-part condensation curable heat conductive silicone adhesive composition that does not react backwards. Stored in two parts, the above parts are:
a) Polymer (i) and cross-linking agent (ii) in one part, and polymer (i) and catalyst (iii) in the other part, or b) Cross-linking agent (ii) in one part, and the other part Polymer (i) and catalyst (iii),
c) When two or more kinds of polymers (i) are used, the first polymer (i) and the cross-linking agent (ii) are in one part, and the second polymer (i) and the catalyst (iii) are in the other part. Or d) a polymer (i) in one part, and a cross-linking agent (ii) and a catalyst (iii) in the other part.
The multi-part condensation curable heat conductive silicone adhesive composition according to claim 1, which may be divided into two parts. The non-reversible multipart condensation curable thermal conductivity according to claim 3, wherein the thermally conductive filler is present in both parts of the composition or in the base portion together with the polymer (i). Silicone adhesive composition. The multipart condensation curable thermal conductivity that does not reverse reaction according to any one of claims 1 to 3, wherein the thermally conductive filler (iv) is present in an amount of 70 to 93% by weight of the composition. Silicone adhesive composition. The thermal conductive filler (iv) is selected from silver powder, aluminum powder, aluminum oxide powder, zinc oxide powder, aluminum powder, and / or graphite nitride, according to any one of claims 1 to 4. The multipart condensation curable heat conductive silicone adhesive composition which does not react in reverse as described. The reverse reaction according to claim 1, 4, 5, 6, or 7, wherein the thermally conductive filler (iv) is a mixture of aluminum oxide, optionally pretreated, of various diameters. No multi-part condensation curable heat conductive silicone adhesive composition. The heat conductive filler
a) Thermally conductive filler with an average particle size of 20-80 micrometers, or 30-50 micrometers, and / or b) Heat with an average particle size of 2-10 micrometers, or 2-6 micrometers Conductive fillers and / or c) Thermally conductive fillers with an average particle size of 0.1 to 1 micrometer or 0.2 to 0.8 micrometers.
The multipart condensation curable heat conductive silicone adhesive composition according to claim 7 or 8, which is a mixture of two or more of the above and is distinguished by an average particle size. A thermally conductive silicone adhesive that is cured from the composition according to any one of claims 1 to 7 and does not react back.
(I) At least one condensation-curable silyl-terminated polymer having at least one, typically at least two, hydroxyl functional groups per molecule.
(Ii)
A silane having at least 2 hydrolyzable groups or at least 3 hydrolyzable groups per molecule, and / or a silyl functional molecule having at least 2 silyl groups, each of which has at least 1 silyl group. A silyl functional molecule containing hydrolyzable groups, or a cross-linking agent selected from the group of mixtures thereof.
(Iii) With at least one condensation catalyst selected from the group of titanates and / or zirconates.
(Iv) One or more heat conductive fillers,
The composition comprising
Ingredients (i), (ii) and (iii) are not contained in the same part,
The molar ratio of total silicon-bonded hydroxyl groups to total hydrolyzable groups is 0.2: 1-2: 1 using silane cross-linking agents, or 0 using cross-linking agents for silyl functional molecules. .2: 1 to 10: 1, and a catalytic M-OR functional group for the total silicon-bonded hydroxyl group [in the formula, M is titanium or zirconium. ] Is included in the molar ratio of 0.01: 1 to 0.5: 1.
The heat conductive silicone adhesive which is the composition and does not react backward. The heat conductive silicone adhesive according to claim 8, which is in the form of a gel or an elastomer and does not react reversely. The encapsulant for an electric or electronic component according to claim 9, which comprises the thermally conductive silicone adhesive that does not react in reverse. An electrical or electronic component encapsulated / embedded in the silicone gel according to claim 9. A protective method for an electric component or an electronic component using the silicone gel composition according to any one of claims 1 to 7. Use of the adhesive according to claim 8 or 9 for sealing, encapsulating, embedding, or filling electrical or electronic components. The method for producing an adhesive according to claim 9, wherein the multipart composition according to any one of claims 1 to 7 is mutually mixed and the obtained mixture is cured. Use of the adhesive according to claim 8 or 9 as a thermally conductive encapsulant or implant for electrical and / or electronic devices, solar cell modules, and / or light emitting diodes. The eighth or nine of claim 8 or 9 in the manufacture of laminates, adhesives, optically transparent coatings as pressure sensitive adhesives, as vibration or sound buffering applications, or for displays or waveguides. Use of adhesive. 11. The method of claim 11, wherein the mixture is applied onto a substrate and then cured using a dispenser selected from curtain coaters, sprayers, die coaters, dip coaters, extrusion coaters, knife coaters, and screen coaters. .. An electric device and an electronic device provided with a member made from a cured product of the heat conductive silicone composition according to any one of claims 1 to 7. A heat radiating member for an electrical device and an electronic device made from the thermally conductive silicone composition according to any one of claims 1 to 7. The heat radiating member according to claim 16, which is in the form of an interface between a semiconductor electronic element and a metal heat sink.